0000125049 00000 n The purification of UDD powders is important for achieving good stable nanofluids. Another method for removing the carbon impurities from the UDD powders is with dry salt or dry sucrose [10]. There are different methods to purify the UDD powders. Here, we perform electrical characterizations of propylene glycol-based ZnO nanofluids with volume fractions as high as 7%, measuring up to a 100-fold increase in electrical conductivity over the base fluid. Yeganeh et al. <50C [21]. WebBNNBs exhibit high thermal conductivity due to efficient phonon transfer and they are electrical insulators owing to their wide bandgap. However, those results have not been collectively compared or discussed. Absolute deviations lower than 1.5% were obtained between the experimental and predicted data using the aforementioned nanopowder thermal conductivities, as can be observed in Fig. The stability, thermophysical properties and rheological characteristics of N-CQDs nanofluids were investigated. [12] also used acid mixtures of perchloric acid, nitric acid and hydrochloric acid (based on the procedure of Jang and Xu [13]) for the removal of carbon impurities from the UDD powders and prepared stable ND nanofluids in the base fluid of 55:45% ethylene glycol/water mixture and observed thermal conductivity enhancement of 18% at 2.0vol.%. The X-ray powder diffraction (XRD), transmission, C, respectively compared to their respective base fluids. 180 30 The PG/W nanofluids are prepared with acid treated ND particles. WebThere are two main types of water glycol mixtures used in heating/cooling systems that mix well in water at any concentration. The earlier works reveals the preparation, estimation of thermal conductivity and viscosity of EG/W mixture based Al2O3, CuO, ZnO and Fe3O4 nanofluids. Yu et al. Results showed that ND nanofluids achieved higher heat transfer coefficients than the base fluid. The present work focused on the preparation of different weight ratio of PG/W (20:80%, 40:60% and 60:40%) mixture based ND nanofluids and the estimation of thermal conductivity and viscosity experimentally at different particle concentrations and temperatures. On the other hand preparation of propylene glycol/water (PG/W) based nanofluids and estimation of thermal properties is also important before use in heat transfer equipments, because these PG/W fluids are also used as engine coolants for automobile radiators. jralston1@ncat.edu, b Different weight or mass ratios of ethylene glycol/water (EG/W) or propylene glycol/water (PG/W) fluids are commonly used as engine coolants for automobile radiators and also used as coolant for electronic equipments, heating industrial and residential buildings in the cold countries of the world such as Alaska, Canada, Northern Europe and Russia, because of its low freezing point i.e. However, experimental studies that jointly explore the physical properties of hybrids and the corresponding mono nanofluids are missing. Additionally, surface tension and electrical conductivity are investigated. Forget about conductivity, it is directly related to temperature and is used in domestic/process water systems (water treatment) where you don't ha Accurate estimation of thermal conductivity (TC) of nanofluids is essential in thermophysical studies of nanofluids. 245-255, Applied Thermal Engineering, Volume 91, 2015, pp. In this particular system we are using an expansion tank with a bladder, so we don't have a make-up pump. A binary mixture of propylene glycol and water at 20:80 mass ratio offers protection against freezing up to 265.98 K [13], making it suitable as a heat transfer fluid The present findings are consistent with those of Palabiyik et al. 0000088462 00000 n It is hygroscopic, meaning that it readily absorbs water from the surrounding environment. Properties for Dowfrost (Propylene Glycol) Electrical conductivity for 50% at 25 deg C = 2,060 micromhos/cm and 249 micromhos/cm for 50% at 0 deg C. Looks 0000060250 00000 n WebIn this work, mono B 4 C and TiB 2 and hybrid TiB 2:B 4 C nanoadditives are used for the first time to design nanofluids based on propylene glycol:water 20:80 wt%. Among all the carbon materials ND particles creates great interest because of their superior hardness, thermal conductivity, i.e. Webconductivity. This study recommends that the volume concentration of Fe3O4/60:40%W+EG nanofluid should not exceed volume concentration of 1.0% because the added benefit of working with concentrations higher than 1.0vol% may not outweigh the added cost and complexities of the nanofluid. These plates are to be used in a proposed compact (thin and light-weight) solar thermal flat plate collector (FPC). An enhancement of 4.24% in heat transfer rate was observed with 2vol.% ZnOPG nanofluid. The overall heat transfer coefficient and nanofluid-side heat transfer coefficient under constant bath temperature condition were found to increase with increasing nanoparticle volume concentration. In this study, the thermal conductivity of graphene/propylene glycol nanofluids is tested using the Hot Disk TPS-500S thermal constants analyzer (Hot Disk AB, Gteborg, Sweden). 181-190, International Journal of Heat and Mass Transfer, Volume 129, 2019, pp. Nanofluids offer many opportunities to enhance the efficiency of thermal systems by improving the thermal properties of the host fluids. New thermal conductivity and viscosity correlations have been developed based on the experimental data. The present work shows an innovative frame saw machine to cut granite, the eccentric hinge guide mechanism is introduced into the machine. Future research should focus on enhancing the dispersion stability of BNNB nanofluids and exploring the influence of BNNB morphology on the thermal conductivity and other thermophysical properties of nanofluids. The purchased UDD powders treated with strong acid treatment, dry salt and dry sucrose to make them into single ND-crystals. Naik and Sundar [28] prepared 30:70% PG/W based CuO nanofluid and estimated thermal conductivity and viscosity experimentally. The GMDH model showed a better performance compared to GEP, and could predict all data with an average absolute relative error of 2.27% in training and 2.44% in testing data set. Based on the results, the thermal conductivity enhancements are 18.8%, 16.8% and 14.1% at 1.0 vol.% of 20:80%, 40:60% and 60:40% PG/W based nanofluids. Similarly, at 1.0vol% and Reynolds number of 2702, the thermal entropy generation is dropped by 38.12%, frictional entropy generation is raised by 12.86%, exergy efficiency is enhanced by 36.48% and thermal performance factor is augmented by 1.2094 times over the base fluid. Ghazvini et al. About 26% increase in coolant side heat transfer coefficient was obtained with 2vol.% ZnOPG nanofluid under constant bath temperature condition which could be attributed to thermal conductivity enhancement as well as improved natural convection due to viscosity reduction. The reason for the agglomeration of UDD powders in the base fluid is due to the presence of carbon impurities. The proportion of micro-fractured and good diamonds in the new frame saw machine are 45% and 25%, respectively, and the productivity of the new machine is between 6 and 15m2/h. After cycling at 25 and 80 C, LiGe alloy was formed at the Li/LAGP interface as investigated by synchrotron high energy X-ray Diffraction (HEXRD) spectra (Figure 3b ). Check with Union Carbide or Dow as they manufacture glycols. I understand they do have a web site. startxref MEG (Mono Ethylene Glycol) or C2H6O2. The earlier works reveals the preparation, estimation of thermal conductivity and viscosity of PG/W mixture based Al2O3, CuO, and Fe3O4 nanofluids. [34] for Al2O3/PG and TiO2/PG nanofluids. 0000000918 00000 n Comparisons with data from literature confirmed the validity and the suitability of the nanoflash technique applied to thermal conductivity evaluation. Reynolds numbers were in the range 10100 and fluid inlet temperatures ranged from 5 to 40C. 40-48, Applied Thermal Engineering, Volume 90, 2015, pp. The sensitivity analysis illustrated that temperature has the highest effect on the relative TC followed by base fluid TC and particle volume fraction. These values are significantly larger than that of the marble frame saw. A shell and helically coil heat exchanger (SCHE) is used to experimentally investigate the performance of 60% water and 40% ethylene glycol mixture based Fe3O4 nanofluid as a coolant. [27] analysis if the value of C/Ck<4 then the nanofluid is heat transfer beneficial fluid. [30] also prepared 20:80%, 40:60% PG/W based Fe3O4 nanofluids and estimated thermal conductivity and viscosity experimentally. ScienceDirect is a registered trademark of Elsevier B.V. ScienceDirect is a registered trademark of Elsevier B.V. 2023, Thermal Science and Engineering Progress, 2023, International Journal of Thermal Sciences, 2022, International Communications in Heat and Mass Transfer, Diamond and Related Materials, Volume 69, 2016, pp. In the heat exchanger, the hot fluid passes through the shell side and the cold fluid (nanofluid) passes through the helical coil side. Increasing the concentration of the nanofluid beyond 1.0vol% shows a little improvement in the effectiveness of the heat exchanger. Prasher et al. The dataset includes 13 different nanofluids with temperature from 30.00 to 149.15C, particle size from 5.00 to 150.00nm, particle thermal conductivity from 1.20 to 1000.00W/mk, particle volume fractions from 0.01 to11.22%, and base fluid thermal conductivity from 0.11 to 0.69W/mk. <]>> The study also investigated the dispersion stability of BNNBs in different solvents using Hansen Solubility Parameters, revealing that propylene glycol mixtures demonstrated better long-term stability compared to ethylene glycol mixtures. An investigation has been undertaken into the stone processing machines. The thermodynamic, heat transfer and thermal performance factor were analyzed experimentally at different particle volume loadings of water+ethylene glycol mixture based nanodiamond (ND) nanofluids flow in a shell and helical coiled tube heat exchanger. Sundar et al. 0000002832 00000 n [27] prepared PG based Al2O3 nanofluids and estimated viscosity experimentally and proposed viscosity model. Copyright 2023 Elsevier B.V. or its licensors or contributors. [14] also used strong acids of H2SO4 and HNO3 in the molar ratio of 3:1 for the purification of UDD powders and prepared 20:80%, 40:60% and 60:40% ethylene glycol/water mixture based ND nanofluids and estimated both thermal conductivity and viscosity experimentally. WebIn this study the electrical conductivity of aluminum oxide (Al2O3), silicon dioxide (SiO2) and zinc oxide (ZnO) nanoparticles dispersed in propylene glycol and water mixture Results show, at 1.0vol% and the Reynolds number of 2702, the heat transfer coefficient and Nusselt number is increased by 36.05%, and 27.47%, respectively, over the base fluid. The values of Ck and C for all the volume concentrations and, The purchased UDD powders were successfully treated using strong acids, dry powders of salt and sucrose to remove carbon impurities. They also observed the formation of carboxyl groups on the surface of ND particles based on the FTIR analysis. New thermal conductivity and viscosity correlations have been developed based on the experimental data. provided correct acknowledgement is given. During the preparation of UDD powders, igniter is used in the detonation process which causes metal and carbon impurities and those are aggregates or attached to the outer surface of the ND particles. Xie et al. The results show that the contact area between the blade and granite is not following a straight line, and the time required for stone sawing is only one half of the full sawing cycle. 2 shows the IR spectra of UDD powders, acid treated, salt and sucrose milled samples. 0000088822 00000 n If you are the author of this article, you do not need to request permission to reproduce figures Read more about how to correctly acknowledge RSC content. You do not have JavaScript enabled. To request permission to reproduce material from this article, please go to the 0000102258 00000 n For 1.0% and a Reynolds number of 1454.4, the thermal performance factor is increased by 1.194-times above the basic fluid. [25], [26] also prepared 20:80%, 40:60% and 60:40% EG/W based Fe3O4 nanofluids and measured both thermal conductivity and viscosity experimentally. It was observed that the position of the thermocouples can result in an under-estimation of the Nusselt number. 209 0 obj<>stream 0000086902 00000 n The thermal entropy generation is decreased by 31.78% and the frictional entropy generation is raised by 22.50% over the basic fluid data at 1.0% and Reynolds number of 1454.4. When compared to Propylene glycolwater (50:50) along with Propylene glycolwater (50:50) dispersed with 0.25% Graphene, it is clear from Fig. 0 The B4C mono nanofluid shows the highest improvements of thermal conductivity (6.0%) and electrical conductivity (70 times higher), but also the highest viscosity increases (5154%). 1123-1135, Experimental thermal conductivity and viscosity of nanodiamond-based propylene glycol and water mixtures, https://doi.org/10.1016/j.diamond.2016.07.007, nm can be produced in large quantity by using commercially available ultra-dispersed diamond (UDD) powders. Measuring glycol concentrations by electrical conductivity is not recommended, especially in process systems, heat exchangers, etc. The quality of For reliability, Electrical conductivity of aqueous Propylene glycol (PG/W-30/70) is determined (30EG/70W) as a for three times and the same is compared with 0000073219 00000 n The acid treated ND particles were characterized by XRD, TEM, FTIR and XPS. This paper presents results of experimental investigation into dielectric properties of silicon oxide lignin (SiO 2-L) particles dispersed with various mass fractions in ethylene glycol (EG).Measurements were conducted at a controlled temperature, which was changed from 298.15 to 333.15 K with an accuracy of 0.5 and 0.2 K for dielectric WebUsing the results for propylene glycol/water with corrosion inhibitor and nanoparticles, for over 3,000 hours of operation, the conductivity of the solution would have gone up to about 27 mS/cm-hr. Common uses: antifreeze/heat transfer fluid. The carbon impurities present in the UDD powders is removed with strong acid treatment, dry salt and dry sucrose to make them into single ND crystals. p^h72n* 8pW&.=rfeK&=d_">!f4-6%)|Z>,^R :qz*jn88H1 Z'2P?[-ik,2T0!L The ultra-sonication technique was employed for preparing the mixture and results showed that the stability and thermal conductivity enhancements of Al2O3H2O nanofluids are highly dependent on sonication time and the energy supplied to the fluid for its preparation. The carbon based materials such as multi walled carbon nanotubes (MWCNT), single walled carbon nanotubes (SWCNT), graphene and nanodiamond (ND) materials contain high thermal conductivity compared to other materials. The hybrid nanofluid presents intermediate values between those of the mono nanofluids for all the properties except dynamic viscosity. The theoretical models of Maxwell and Einstein have failed to estimate the thermal conductivity and viscosity of nanofluids as a function of temperature. The single phase heat transfer fluids such as water (W), ethylene glycol (EG), propylene glycol (PG) and engine oil (EO) are primarily used in may industrial applications, among others, power, chemical and food industries. Glycol soutions are fed (topped-off) buy a pumped glycol feeder available by JL wingert, armstrong, etc Heat exchanger tubes are .035" wall I've ne The preparation of ND based nanofluids and their thermal properties are given below. Drazen, you seem to have drifted from the original question. The problem is glycol in the condensate which could be fatal to the boiler. We need 0000047379 00000 n WebMaintains low electrical conductivity Uses proprietary non-ionic corrosion inhibitor formulation with years of research Can be used with Formulation: Propylene Glycol, Joint School of Nanoscience and Nanoengineering, University of North Carolina at Greensboro, Greensboro, NC 27401, USA. A sawing test and a simulation were carried out to analyze the sawing trajectory, the surface topography of the segments and the percentage of worn diamond particles. Experimental research was done on the heat transfer, entropy generation, and exergy efficiency of ethylene glycol (EG) based nanodiamond (ND) nanofluids flowing in a circular tube. [27] model and Mouromtseff number [31] is used to study the heat transfer benefits of PG/W based ND nanofluids in laminar and turbulent flow conditions. BNNBs exhibit high thermal conductivity due to efficient phonon transfer and they are electrical insulators owing to their wide bandgap. WebThermal conductivities for some common liquids at temperature 300 K (26.8 oC, 80.3 oF): 1 W/(m K) = 1 W/(m oC) = 0.85984 kcal/(h m oC) = 0.5779 Btu/(ft h oF) = 0.048 Btu/(in h 0000003207 00000 n xref 0000017674 00000 n Vajjha and Das [24] also prepared 60:40% (weight ratio) of EG/W based Al2O3, CuO and ZnO nanofluids and measured thermal conductivity up to 10.0vol.%. Correlations for the thermo-physical properties of the nanofluid were developed. The Raman, XRD and TEM analysis are also used on UDD and ND-acid treated nanoparticles. to access the full features of the site or access our, Joint School of Nanoscience and Nanoengineering, North Carolina A&T State University, Greensboro, NC 27401, USA, Joint School of Nanoscience and Nanoengineering, University of North Carolina at Greensboro, Greensboro, NC 27401, USA. 0000087804 00000 n The thermal conductivity and viscosity of ND nanofluids were investigated experimentally, whereas the density and specific heat were estimated theoretically. , DOI: 10.1039/D2NR06332H. The local Nusselt number was observed to vary axially despite satisfying the criteria for neglecting entrance effects; this variation increased with the Graetz number. At 1.0vol% of nanofluid and a Reynolds number of 1454.4 in comparison to the base fluid, the Nusselt number and heat transfer coefficient are boosted by 29.43%, 45.01%, and a friction factor penalty of 27.59%, respectively. This study investigates the potential of composite allotrope boron nitride nanobarbs (BNNBs) as nanoparticles for enhancing the thermal conductivity of nanofluids based on mixtures of ethylene glycol and propylene glycol with water. 0000002101 00000 n Copyright Clearance Center request page. A. O. Maselugbo, B. L. Sadiku and J. R. Alston, Webviscosity, a relatively high specific heat and thermal conductivity, as well as good mixing with water and alcohols cause the ethylene glycol to be widely used in practice [13]. . Web9.9 Liquid Water Interfacial Tension: Not pertinent 9.10 Vapor (Gas) Specific Gravity: Not pertinent 9.11 Ratio of Specific Heats of Vapor (Gas): 1.073 9.12 Latent Heat of Vaporization: 306 Btu/lb = 170 cal/g = 7.12 X 105J/kg 9.13 Heat of Combustion: 10,310 Btu/lb = 5,728 cal/g = 239.8 X 105J/kg 9.14 Heat of Decomposition: Not pertinent The eccentric hinge guide mechanism facilitates the formation of both matrix tails on the segments and a group of more new micro cutting edges, which improve diamond stability as well as self-sharpening. WebPropylene Glycol Methyl Ether (PM; CAS No. The thermal conductivity results here reported can be compared with those previously published by Sundar et al. Annual production of propylene glycol in The propylene glycol/water mixtures at different weight ratios were used as base fluids for the preparation of stable ND nanofluids. The frictional exergy destruction is found to contribute together with heat transfer exergy destruction to the total entropy of the SCHE system. Since water is seen as the golden standard in thermal conductivity, higher concentrations of ethylene glycol in a water solution will cause heat to pass through it slower, therefore, the lower the amount of ethylene glycol in the mixture, the more efficient it is at conducting heat. Download : Download high-res image (216KB)Download : Download full-size image. in a third-party publication (excluding your thesis/dissertation for which permission is not required) An enhancement of thermal conductivity with respect to temperature and volumetric concentration is found, as expected. The main advantages of this measurement technique are short measurement times, easy sample preparation and high accuracy. Prediction of electrical conductivity of TiO 2 water and ethylene glycol-based nanofluids for cooling application in low temperature PEM fuel cells. Jee and Lee [11] used strong acids of H2SO4 and HNO3 in the molar ratio of 3:1 for the purification of UDD powders and observed the removal of carbon impurities. The electrical conductivity of glycol mixtures within the range of 1000W/mK and Young's modulus, high electrical resistivity, attractive optical characteristics, and excellent chemical stability and biocompatibility. Our results indicate that the surfactant-free, ZnOPG nanofluids behave like liquid coolants but with improved thermal conductivity and specific heat and hence suitable for energy management. We are continuing our optimization to bring this level down by an order of magnitude (which is accepted by almost all the fuel cell manufacturers). The relative electrical conductivity of -SiC NFs and model predictions determined at 298.15 K are compared as illustrated in Fig. In this study, more than 3200 data of thermal conductivity of nanofluids were collected from literature to develop simple-to-use and accurate correlations for predicting relative thermal conductivity of nanofluids. 115-123, International Communications in Heat and Mass Transfer, Volume 76, 2016, pp. 8 . Therefore, there is no literature on the thermal properties of PG/W mixture based ND nanofluids. The heat transfer applications of prepared ND nanofluids in a fully developed laminar flow (Reynolds number, Re<2300) can be evaluated based on the Prasher et al. Appl. The specific heat capacity decreases with increasing nanofluid loading. Experiments were performed to study the transient heat transfer characteristics of probe-ultrasonicated, surfactant-free, ZnOpropylene glycol (ZnOPG) nanofluids under constant heat flux and constant bath temperature conditions. WebElectrical Conductivity ( S/cm) 55% Propylene Glycol + 45% DI Water + 0.1% Benzotriazole + 0.05% Nanoparticles (Mix# 2) 55% Propylene Glycol + 45% DI Water + 0.1% Benzotriazole + 0.025% Nanoparticles (Mix# 2) Electrical Conductivity vs. Time for the Coolant Formulations in a 1 L Dynamic Test Loop at 70oC 11 0000002868 00000 n The instrument is based on transient plane source (TPS) technique and is widely used for thermal conductivity measurement. Conductivity is also affected by temperature: the warmer the water, the higher the conductivity. and diagrams provided correct acknowledgement is given. Chemical co-precipitation was used for the synthesis of large quantity of Fe3O4 nanoparticles with an average particle size of 11.42nm. Energy . The results are beneficial for the design and operation of micro-channel absorber plates. 0000002234 00000 n Nanoscale, 2023, Advance Article The ultra-dispersed diamond (UDD) powders were purchased from International Technology Centre, USA (http://www.itc-inc.org) with the following specifications: 98% purity, 510nm particle core size, cubic shape, grey color, 300400m2/g specific surface area. Effects of working temperature on thermo-physical properties and forced convection heat transfer of TiO 2 nanofluids in waterEthylene glycol mixture. Diamond circular saws and diamond wire saws present some technological limits, and the marble frame saw cannot process granite by now. The functional groups on the treated UDD powders were analyzed by FTIR. To create stable nanofluids, the ND nanoparticles are ultrasonically agitated with EG for 4h. At a constant heat flux of q=9099W/m2, experiments were carried out in a laminar flow with Reynolds numbers ranging from 264.4 to 2194.4. The synthesized environmentally friendly N-doped carbon quantum dots nanoparticles (N-CQDs) had a uniform particle size distribution, with particle sizes concentrated between 2 and 2.5nm. The Choi [1] and his team developed nanofluids (fluids contain nanometer size particles) and obtained higher thermal conductivity compared to base fluids. Group method of data handling (GMDH) and gene expression programming (GEP) as two white-box powerful models were used for modeling. Branson et al. [15] observed thermal conductivity enhancement of 12% at 0.9vol.% of nanodiamond (ND)-poly (glycidol) polymer brush/EG nanofluids, similarly observed thermal conductivity enhancement of 11% at 1.0vol.% of ND.oleic acid/mineral oil nanofluids. The results showed that the Turbiscan stability index of N-CQDs nanofluid was about 1.5 and the T value fluctuated within 0.5%, showing excellent stability. The hot fluid volume flow rate was fixed to 1 lit/min, whereas, the cold fluid (nanofluid) volume flow rate was varied from 2 to 6 lit/min. %%EOF endstream endobj 181 0 obj<. BNNBs are allotrope composites composed of boron nitride nanotube cores with walls decorated with attached hexagonal boron nitride crystals, creating a jagged morphology that facilitates the formation of a connected network and contributes to the enhancement of thermal conductivity in nanofluids. The effect of BNNB concentration in carrier fluids on nanofluid thermal conductivity was investigated by introducing BNNBs into ethylene glycol-water and propylene glycol-water mixtures at 010 wt%. 0000133274 00000 n The formation of carboxyl (COOH) groups on the surface of ND particles was analyzed by FTIR spectrum. [23] first time prepared 60:40% (weight ratio) of EG/W based CuO nanofluids and observed viscosity enhancement of 4.5-times and 3.1-times at 6.12vol.% at temperatures of 35C to 50C. Kole and Dey [29] prepared 50:50% PG/W based Al2O3 nanofluids and observed nanofluids obey Newtonian behaviour in the measured temperature range from 10C to 50C. [27] analysis.knfkbf=1+Cknfbf=1+Cwhere, is the volume concentration, Ck and C are the thermal conductivity and viscosity enhancement coefficients. This paper reviews and summarizes the experimental values of the physical and thermal properties, including an appropriate focus on the thermal conductivity enhancement, of nanodiamond-nanofluid systems found in the literature as well as different techniques for thermal conductivity measurement. The heat transfer capability of these single phase heat transfer fluids is limited because of its poor thermal conductivity. The other chemicals such as sulfuric acid (H2SO4), nitric acid (HNO3), sodium chloride (NaCl), sucrose (C12H22O11) and propylene glycol (C3H8O2) were purchased from Sigma-Aldrich Chemicals, USA.
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